Pressure core barrel



April l5, 1941. B. w. sEwELL 2,238,609

PRESSURE GORE `BARREL y Filed April 21, 195s :s sheets-sheet 2 i -18 z$49 2 7-90 vfag .a /91 g LA I Y April l5, 1941. B. w. sEwELl.A`2,238,609

` PRESSURE CORE BARREL FuedApril 21, 195s s sheets-sheetr s 8 2 7 www nn4m 6.,67 7n WM 2 m 6 8. mw. @A l. 3 6. ..1 1H 7 .,M.. u\\\\\\ il In /W7% F H 1. Ov. B. 8 @w m F 9 5 U 5. u E- Pu. WENN/M F F 2 8 ,8.88

, companying drawings in which- 'Patented Apr. 1s, i941` PRESSURE COREBARREL w. seweu, ruin, om., minore Standard Oil Development Company; a-oorpo-` ration of Delaware application April ci, 1999, serial No, 26ans19 Claims.

`The present invention is directed to a coring device for securing acore from a substratum under the pressureobtaining in the substratum.

The principal object of'the present invention is the provision ofa-coring devicefof the character described including aa-longitudinal,retractable barrel' for receiving a core and means independ-Y endof'which is in threaded engagement with a cylinder I, the upper endof-'which is, `in turn, in Y entof said--barrelfor sealing thecoreunderthef,

pressure of the formation from which -it was obtained, in which themeans for sealing the lower end of the core is operated simply byraising the drilllstem.

additional object 'of-the 'present invention is the ,provision ofmeansof the character described in whichV is provided a valve for sealing offthe lower end of the core barrel of such a i construction that duringthe c oring operation it is subjected to the flushing action `of thedrilling fluid. l

, A further object of the present invention is the provision of afdeviceof the character described including a core .barrel and a shellsurrounding said barrel land normally xed for movement therewith inwhich means are provided for breaking the connection between theseelements before the beginning of the coring operation.

Another object of the present invention is the threadedengagement Vwitha collar- 6 slidingly mounted on a section 1 Aof reduced diameter of a4nipple 8 carried by a drill stem '9.' 'Iheins'ide` edge of the bottomend of collar 6 is beveled asV at Il to receiveisimilarly inclined facesof dogs II, each of which is'pivoted on a pin I2 in a lonlgitudirlalslotI3 in the wall of section 1 At `its -freeend each of these dogs carriesa leafspring I4, the endcf whichfpresses againstthev inner i, face of,sectionY 1 and normally tends to press the dogs inwardly .toward thecenter of section I out provision of novely means for breaking oil? acore from the formation from `which it is cut.

`Further objects and' novel features 'and fadvantages'ofv the presentinvention will appear from the following detailed-description of the ac-Figs. 1, 2 and 3 constitute together a side view, partly in quartersection and partly in-ha-lf section, of a coringdevice according to thepresent invention, said figures being arranged in sequence beginning atthe bottom of the coring device;

Fig. 4 is a section .of the core barrel along the vplane at right anglesto the -sectional view of Fig. 5 is a cross section on Fig. 3:

Fig. 6 Fig. l:

Fig.. 'I is a cross section along the-line BF-B of Fig. 1;

the line A.- of

1s a detailed viewfo: the vaivesnown in Fig.8 is a cross section alongthe'lineC-C of4 Fig. 1; and y Fig. 9 is va detail view of the corecatcher. Referring to the drawingsv in detail, numeral I designates aconventional core drill head pro'- vided with conventional cone cutters2 and with a centrall passage I. The core head is held inthreadede'ngagement with a collar l, the upper of engagement with collarB. i

The inner face of each dog l I is provided with a ledge I5, the outeredge of which is turned up in the /formof a lip I6, said lip' being ofsuch` configuration as to fit into an annular recess I1 provided on theundersurface of a head I8 carried by 4sleeve I9 slidingly mounted on arod 20 which is provided at some distance from its end with a shoulder2l to limit the movement of' sleeve I9 at that direction, and isprovided with a nut I22 between which and the head I8 is arranged ahelical spring 23 which normally forces sleeve I9 against shoulder 2|.

:The rod 21|4 is connected at its lower end with a- Acoupling 2l' to.which is also 'connected a rod 25 in alignment with rod 2|i,`whichcarriesiat its lower 'end through vconnections hereinafter described abarrel .26. f i

The lowerv end of the barrel 20 rests on a ledge 21 provided on theinner surface of a small tube 28 arranged in passage 3 and. threaded tothe inner faceof the lower end of collar I,- lThe lower edge of tube 28is serrated to form Acutting teeth in the conventional manner.

and the lower end of barrel 28, and is connected to the former by ashear pin 3| and to the latter by a shear pin` 32. In each case the endof the shear pin which is in the plug is carried bya ring of hard metalwhich is provided so as to l avoid the necessity of making the' wholeplug of hardmetal which might cause some drilling difficulties if theplug should become lost in the hole.` VSincethe barrel 2l and tube 28are rig' idly connected to each other and the latter is rigidlyconnected to collar I and the former to rod 20, it follows that, whilepins 3l and I2 arein the position shown, theparts will remainr in therelationship shown.

Abovevthe cutting head the collar I is provided t on` its inner facewitha shoulder 32 upon which rests a cylindrical valve head `Il which iscon- A plug 29 having a central passage 30 is arranged inside of tube 23through which rod 25 passes.

ried by a sleeve 35 which is also concentric with barrel 26. Sleeve 35is of greater length than barrel 26 and carries at its upper end acylindrical block 36 which has a central bore 31 Atits lower end, thiscentral passage 31 is enlarged whereby an annular space 36 isformedbetween its inner face and the rod 25. A radial passage 39connects space 38 with the exterior of the block. Ihe block is alsoprovided with-a laterally offset longitudinal passage 46 controlled by aneedle valve 4| and, when open, making connectionv with a lateralpassage'42 provided with a plug 43 for the purpose hereinafter specied.Block 36 is provided with radially-extending longitudinal'ins 64 whichspace i t from cylinder 5.

Extending upwardly from block 36 is a. sleeve' 44 concentric withcoupling 24, said sleeve nor-I mally having Ya smaller interior diameterthan the outside diameter of coupling 2 4, but being reamed out to forma sliding fit for said coupling for a length defined by shoulders 45 and46, whereby said coupling is permitted limited longitudinal movementwithin said sleeve for the purpose hereinafter specified.

At its upper end, sleeve 44 is provided wi `centric with the barrel 26and is, in turn, carjecting into the space between the ribs. On thesestuds is journaled a steel ball 13 'which is provided with an interiorpassage 14 for the v receipt of barrel 26. Sleeve 65 is suitably relcessed just above the cut-away portion 66 to receive a packing ring 15which is of s uch configuration as to form a duid-tight seal with thesurface of the ball13.v At either one of its journaled ends ball'13carries a pinion'16 which is adapted to mesh with a rack 11 carried bythe adjacent ribs 66. Each rack is secured to a rib by screws 18working'in slots 18, said rack being laid against the side face of therib, with its one edge projecting further laterally than the arcuateface of the rib, and is of such a length as to fit' between the lowerend of cylinder 5 and shoulder 33 on collar 4. Thus, while each rack issecured to a rib which,in turn, is integral with sleeve 65, it acts asthough it .were secured to collar 4, that is, it is capableof movementrelative to sleeve 65 and, therefore,

` `relative to the pinions 16.

radially extending longitudinally arranged ins 41 which have inclinedupper edges 48 adapted rto form a seat for'the beveled edge 49 of theinside edge lof the lower end of aforesaid section 1. Section 1 is alsoprovided adjacent its lower end with an external inclined shoulder 56which is adapted to abut against the beveled edge I6 on collar 6 for thepurpose of limiting the relative movement of 'collar 6 and section 1. ashereinafter described. Rod 25 terminates an appropriately selecteddistance below the cylindrical block 36 in a carried by the upper endoi' the valve head.

The valvehead is provided around its circumference with slots 66.belowiwhich is arranged a seat 60 for a ball valve tl,v said seat beingheld in place by a ring 62. The lower end of' the valve head isconnected to the barrel 26 by a Din 63.

The valve head bis composed of a sleeve 66 which has intermediate itsends a cut-out portion 66. The upper end oi'.the sleeve has in ternalthreads 61 which engage threads onthe lower end of sleeve 66, and theremainder ofthe sleeve has an interior diameter equal to that of sleeve66 which is slightly larger than the external diameter of barrel 28. Thev/sleeve is provided with 'diametrlcally opposed longitudinal ribs 68which have rounded'outer surfaces adapted to slldingly engage theinterior of cylinder 6. Each rib is provided with a laterally extendingshoulder 66 which are adapted to.

abutagalnst the lower end of vcylinder 6. :and

.with a shoulder 16 adapted to abut against shoulder 33 of collar 4.lSpaced 90 from the' ribs 66 are short ribs 1| which are used forspacing Purposes.

Each ofthe ribs 66 carries a ystud 12 pro- As previously stated, afeature of the present invention is the core catcher which is shown indetail in Fig. 9. As-can be seen by reference to this figure, the lowerend of barrel 26 is pro'- vided with a circumferential series of spacedslots 68 and with a second series of these slots al spaced from the erstserie-s by bars s2'. Be-

low the latter sries of slots the inner face of the barrel is cut awayto form seats 83. In each of these seats is set one end of a flat member64 of spring steel which is then threaded through the successive slots6| and 60 around the bar 82 with its free endpojecting into the barrel.The

arrangement of slots and bars is such that the/.fV

free end of each flat member is formed into a spring finger normallythrust into the interior of? the barrel. The plug 26 is provided with1ongitudinal recesses 85 to receive these fingers. Likewise, the lowerend of the barrel is provided with longitudinal grooves 66 to receivethesefingers when a core enters the barrel.

Before describing the operation of this device, a brief recapitulationof the relationship of the parts mayl be helpful. The core barrel itselfis carried by the rod 20 and, until the oring operation begins, by theshear pins 3| and 32, the latter being connected t0 the barrel and theformer being connected to the tube 26 which, in turn. is

rigidly connected to collar 4. Collar 4 is rigidly on reduced section 1of nipple 8. In order thatthe rotary movement of drill stem 9 maybetransmitted to the collar 6, the latter is provided with a longitudinalkey 81 which is seated in a slot 66 in reduced section 1. This slot isof suiiicient length to take care of relative longitudinal movementbetween collar 6 and section 1.

In order to prevent the return of collar 6 to the position shown afterthe desired longitudinal movement thereof has occurred, reduced section1 carries dogs 66 which are pivoted on'pins 66, mounted in longitudinalslots 9| Ain section 8 and are spring-pressed outwardly by leaf springs92. When in their outward position, the dogs are adapted to rest on thetop of collar 6 after the latter has 4been moved downwardly thenecessary distance and `to prevent the reverse movement of said collar.As will be apparent, the collar 6 is adapted to slide on the reducedsection 1, its

' Y downward movement being limited by the shoulthe position shownare-dogs II which, in turn are held in position by the head I8 which, ineffect.

l Ais carried by the barrel 26 which, in effect, is

carried by the collar 6. Accordingly, when the connection between thecore barrel and the outer shell, namely the shear pin 3I, isbroken, therelationships shown in the drawings are automatically changed. i

. It will be understood that ln the use of this dei vice drilling mudmust be circulated around-the core cutters. This mud flo-ws `down insideof the drill stern, down around rod 2'0 between fins 41, between thefins 64 of the cylindrical valve head 36, between sleeve 35 and cylinder5 and down outside sleeve 65 to the bottom thereof which is at the topof the drill headwhich, in turn, is

provided with longitudinal passage 93 around its circumference,connecting its upper end with the cutter mountings.

The operation of the core barrel of the present invention is whollyautomatic. With the parts in the position shown, the drill stem islowered to the formation to be cored. When this formation is reached,the weight of the drill stem on the plug 29 first' shears pin 3l, whichcauses relative movement between the barrel 26 and the rest of theassembly for the distance permitted by the clearance between collar 24and shoulder 45. This distance is made just exactly right to permit thehead I8 to clear the lip I6 on each dog II, whereby each lip is forcedby its spring III into the recess I1 provided in head I8 for thatpurpose.

The spring 23 insures a snugv fit between these elements.

Further pressure on the plug 29 shears pi-ns 32 and the coring operationis begun, the plug'29 being pushed up into the barrel by the formationcore. As the core moves upwardly into barrel 26. the drilling mud in thelatter is forced out through passage 33. When suiicient core has beencut, rotation of the drill stem is stopped and the drill stem is lifted.This causes spring fingers 84 t0 break off the core at that'point. Atthis time, the only point of the assembly connected directly to thedrill stem is the core barrel 26, the rest of the assembly being freefor relativemovement with respect to the core barrel by reason ofthedogs lII having been pulled inwardly. Thus, with further upwardmov/ement of the drill stem the core barrel is drawn upi wardly, therest of the assembly resting on the formation until knife edge 53 comesinto contact with its seat 52. i At this point, the'core barrel has beenpulled upwardly a distance sufficient to clear the sleeve 35 to moveupwardly, carrying ff with it. sleeve |55.A The movement of sleeve 65relative to collar 4 causes the pinions 16 to run along the racks 11 androtate the valve 13 suicient to seal off the lower end of the sleeve 35.this point the lower edge I0 0f the collar 6 has still not abuttedagainst the shoulder 50 on section 'L make these abutting sections meet,places the ,spring 23 under compression, thereby tightening the sealbetween the knife edge and its seal and effectively sealing off theupper end of sleeve 35.

Upon further upward movement of the drill stem, therefore, the entireassembly moves upwardly. When the assembly arrives lat the surface, thecollar 4 is unscrewed fromy the cylinder 5, exposing the lower end ofsleeve 35. At this time, the dogs II are exposed by reason of the collar6 having slipped down on section I and the dogs can be prized out ofposition by the application of a screw driver or other instrument tendedto claim it as broadly as the prior art Further upward pull on the drillstem to to the notch shown at the other end, of the dog, or by any otherexpedient. The release of these dogs makes it then possible to slip outsleeve 35 in its entirety from cylinder 5.

The interior of the sleeve 35 is still under formation pressure. Plug 43is removed and connection made with suitable sample collectingapparatus. Then needle valve 4I is opened and the pressure on theinterior of the sleeve allowed to come down to atmospheric, any volatileconstltutents contained in the sample passing oil' to the liquefactionor collecting apparatus for analysis. Upon the release of the interiorpressure of the sleeve, the valve 13 can be `opened and the rod 25 isdisconnected from coupling 24 and the barrel 26 is slipped out of thesleeve.

It will be understood that the device described `above simplyrepresents-the preferred embodiment of the present invention.Manifestly, a great number of mechanical changes can be made therewithwithout departing from the scope of the present invention. Instead ofthe expedients relied upon in the device above described for limitingrelative movements of parts, other expedient means can be employed. Inshort, the present invention is not to be limited by the abovedescription of the accompanying drawings, but only by the appendedclaims in which it is inpermits.

I claim:

l. A device for securing a core from a subsuri face formation comprisinga casing adapted to l be connected to a drill stem for rotationtherewith, a core barrel carried within said casing capable oflongitudinal movement relative thereto and adapted to assume a forwardand a retracted position, means for normally holding said barrel inforward position, and means for releasing said last mentioned means atthe beginningof the coring operation.

2. A device for securing a core from a subsurface formation comprising alcasing adapted to be rotated by a drill stem and capable oflongitudinal m vement relative thereto, a core barrel carried wi hinsaid casing capable of longitudinal movement relative thereto andadapted to assume a forward and a retracted position, means for normallyholding said barrel in forward position and for holding said casing infixed longitudinal relation with respect to said drill stem, and meansfor rendering said last mentioned means inoperative at the beginning 'ofthe coring operation.

3. A coring device comprising a casing adapted to be connected to adrill, stem for rotation therewith and for longitudinal movementrelative thereto, a core barrel carried by said casing, a

4. A pressure coring device 'comprising an outer casing, an inner casingconcentric with and spaced from said outer casing, a barrel mounted insaid inner casing, a cutting head carried by said outer casing havingcutters defining 4a'central passage in alignment with said barrel, andmeans for holding said outer casing, said. inner casing and said barrelin fixed longitudinal relationship, with the latter in communicationwith said central passage, comprising a shear pin adapted to be shearedat the beginning of the coring operation.

5. A device for securing a core from a subsurface formation comprisingan outer casing adapted to be connected to a drill stem vfor rotationtherewith, an inner casing concentric with said outer casing and mountedfor limited longitudinal movement relative thereto, a core barrelconcentric with said inner casing and mounted within said casing forlimited longitudinal movement relative thereto, a cutting head carriedby said outer casing having cutters defining a central passage inalignment with said core barrel, and a plug mounted in said passage andconnected to said outer casing and said core barrel by shear pins andhaving its end projecting below 'the cutting 'head whereby, when theassembly is pressed against the formationto be cored under the weight ofthe drill stem, said pins are sheared and said barrel is freed forlongitudinal movement relative to said outer casing.

6. A device for vsecuring a core from a subsurface formation comprisingan outer casing connected to a drill stem for rotation therewith, meansfor normally holding said casing in xed longitudinal relationship withsaid drill stem, an inner casing concentric with said outer casing andmounted for limited longitudinal movement relative thereto, a Acorebarrel carried by said inner casing and mounted for limited longitudinalmovement relative thereto, means for normally holding said core barrelin a fixed longitudinal relationship with said outer casing, and.

' means actuated by the weight of the drill stem for disengaging saidlast mentioned means and simultaneously freeing said outer casing forlongitudinal movement with respect to said drill stem and for connectingsaid barrel to said drill stem for longitudinal lmovement therewith.

7. A device. for securing a core from a subsurface formation comprisingan outer casing adapted to .be rotated by a drill stem and capable oflimited longitudinal movement relative thereto,4an inner casingconcentric with said outer casing and capable of limited longitudinalmovement relative thereto, a barrel mounted within said innencasing andcapable of longitudinal movement relative thereto, said barrel beingadapted to assume a forward and a retracted l position in said innercasing, means carried by said barrel for sealing off the upper end ofsaid inner casing, when said barrel is in its retracted position, acutting head carried by said casing having cutters defining a centralpassage in alignment with and in communication with the interior of saidbarrel, when it is in its forward position, a valve carried by theforward end of said inner casing and located between said cutting headand said barrel when the latter is in its retracted position, means forretracting said barrel after the completion of the coring operation, andmeans actuated by the retraction of said barrel for closing said valve.

8. A device for securing a core from a subsurface formation comprisinganv outer casing adapted lto be connected to a drill stem for rotationtherewith, an inner casing concentric with said louter casing, a corebarrel slidingly mounted in said inner casing and capable of assuming aforward and a retracted position, a cutting head "r In) carried by saidouter casing having cutters defining a central passage in alignment withand in communication with said barrel when it is in its forwardposition, a valve carried by said inner casing between said headandfsaid barrel when the latter is in its retracted position, means for,

moving said barrel from its forward position to its retracted positionafter the completion of the coring operation, and means actuated by theretraction of said barrel forl closing said valve.

9. A device for securing a core from a subsurface formation comprisingan outer casing adapted to be connected to a drill stem for rotationtherewith, an inner casing concentric with said outer casing and mountedfor limited longitudinal movement relative thereto0 a barrel slidinglymounted in said inner casing capable of assuming a forward and aretracted position, a

Vcutter head carried by said outer casing having cutters,- deiining acentral passage in alignment with and in communication with said barrelwhen it is in its forward position, a valve carried by the lower end ofsaid inner casing ata point between said cutter head and said -barrelwhen the latter is in its retracted position, complementary meanscarried by the upper end of said barrel and the upper end of said innercasing for sealing the upper end of the latter when the barrel is in itsretracted position, means for moving said barrel from its forward to itsretracted position after the completion of the coring operation, andmeans actuated by the retraction of said barrel for closing the valve atthe lower end of the inner casing.

10. A device for securing a core from a subsurface formation comprisinga casing adaptedV to be connected to a drill stem for rotation therewithand for limited longitudinal movement relative thereto, a core barrelmounted within said casing for longitudinal movement relative to saiddrill stem, means carried by said drill'stem for normally holding saidcasing in fixed longitudinal relationship with said drill stem, andmeans actuated by the weight of the drill stem on the assembly fortransferring said last mentioned means from the casing to the core'barrel, to thereby make said core barrel move longitudinally with saiddrill stem.

11. A device for securing a core from a subsurface formation comprisingan outer casing for longitudinal movement relative thereto and .capableof assuming a forward and a retracted position, a cutter head carried bysaid outer casing having cutters dening a central passage in alignmentand in communication withA said barrel when it is in said forwardposition, a valve carried by the lower end of said inner casing having acentral bore for the passage of said core barrel and being adapted to beclosed by the retraction of said core barrel into said inner casing,means severable by the weight of the drill stem on said assembly fornormally connecting said barrel in forward position to'said cutter head,means for imparting longitudinal movement to said barrel relative to-4said outer casing upon the severance of said connecting means. and meansset into operation by said movement of said barrel for transferring thefirst mentioned means from said outer casing to said barrel to therebymake said barrel movable longitudinally with said drill stem.

12. A device for securing -a core vfrom a subsurface formationcomprising an outer casing adapted to be rotated by a drill stem, 4aninner casing concentric with and spaced from said outer casing for thepassage ofdrilling fluid, a core barrel slidingly mounted in said innercasing and adapted to assume a -forwardand a retracted positioma cutterhead carried by said outer casing, having cutters defining a centralpassage in alignment with and in communication with said barrel when itis in saidforward position', a. rotatable valve mounted in the lower endof said inner casing at a point between said cutter head and said barrelwhen the latter is means actuated by the retraction of said barrel forclosing the valve at the lower end of said inner casing.

17. A device according to the preceding claim lincluding means forholding said barrel in its retracted position.

18. A device for securing a core from a subsurface formation comprisingan -outer casing adapted to be -connected to a drill stem for rotain itsretracted position and having a central A bore adapted to receive saidbarrel when it is in its forward position, the walls of said innercasing being cut away adjacent said valve whereby the fluid circulatingbetween said inner casing and said outer casing has access to saidvalve.

13. A device according to claim '7 including means for holding. the corebarrel in its retracted position.

14. A device according to claim 8 including means for holding the corebarrel in its retracted position.

15. A device according to claim 9 including means for holding the corebarrel in its retracted position.

16. A device for securing a core from a` subsurface formationlcomprising an outer casing adapted to be connected to a drill stem forrotation therewith, an inner casing concentric with and spaced from saidouter casing and in open fluid communication with said outer casing atboth`of its ends, a core barrel having an open lower end and beingslidingly mounted in said i inner casing at its lower end between saidhead and said barrel when the latter is in its retracted position,complementary means carried by the upper end of said barrel and theupper end of said l inner casing for sealing the upper end of said innercasing when laid barrel is in its retracted position, means for movingsaid barrel from its forward position to its retracted position aftery Ythe completion of the coring operation, and

.tion therewith, an inner casing concentric with said outer casing andmounted for limited longitudinal movement relative thereto,ia coreVbarrel slidingly mounted in said inner casing and capable of assuming aforward and a retracted position, a, cutting head carried by said outercasing having cutters defining a central passage in i alignment and incommunication with said barclosing said valve.

19. A device for securing a core from 'a subsurface formation comprising'an outer casing adapted to be connected to a drill stem for rotationtherewith, aninner casing in open uid communioatio'n with and concentricwith said casing and mounted for limited longitudinal movement relativethereto, a core barrel slidingly mounted inl said inner casing andcapable of assuming a forward and a retracted position, means carried bysaid barrel for sealing off the upper end of said inner casing 'whensaid barrel is in its retracted position, a cutting head carried by saidouter casing having cutters denning a central passage in alignment andin communication'with said barrel when it is in its forward position, avalve carried by said inner casing between said head and saidbarrel'when the latter is in its retracted position, means for movingsaid barrel from its forward positionto its retracted position after thecompletion of the coring operation, whereby the upper end of said innercasing is sealed olf and further upward movement of said barrel causessaid inner casing to move upwardly relative to said outer casing,andmeans operatively associated with said vinner casing and said outercasing for closing said'valve upon,reiative longitudinal motion betweensaid casings.l

BENJAMIN W. SEWELL.

cooperating

